The present invention relates to a power transmission arrangement for a compactor, in which a roller is installed rotatably by its ends in the end-piece of each roller frame, in such a way that, in each end-piece, the end of the roller is supported in bearings, and at least in one end of the roller there is a ready-made hub motor, which is arranged to rotate the roller, and which hub motor includes, at opposite attachment ends, a casing and a flange, and, between them, bearings that restrain the attachment ends axially, which bearings form the bearing assembly of the aforesaid roller.
Compactors according to the invention are used to effectively compact materials and to crush material. Due to this, the compactors are heavy and have cylindrical rollers as wheels. On account of the large masses and slow driving speed, hydrostatic transmissions are preferably used in the compactors. Usually, the compactor""s diesel engine is used to rotate one or more hydraulic pumps. The hydraulic pumps are used in turn to rotate hydraulic motor units arranged to rotate the rollers. Normally, there is at least one hydraulic motor unit in connection with each roller.
In compactors, the roller is support rotatably by means of bearing assemblies in the end-pieces of the roller frame. In small and narrow compactors, it is relatively easy to locate the hydraulic motor unit directly in the end of the roller, as disclosed in U.S. Pat. No. 4,089,616, for example. Often, only a low-speed hydraulic motor is used as the hydraulic motor unit in small compactors. In larger compactors, the power required is considerable, so that, in addition to the hydraulic motors, some form of gearbox is required. By locating the hydraulic motor, the gearbox, and the bearing assembly in the end of the roller, the compactor""s transmission arrangement becomes complicated and expensive. At the same time, the transmission arrangement requires a great deal of space for installation. In addition, in large compactors, it is difficult to align a hub motor, which is as such known, with the axis of rotation of the roller. Thus, in large rollers, the chain-drive arrangement according to publication U.S. Pat. No. 4,854,772 is generally used.
The invention is intended to create a compactor transmission arrangement, which is simpler than previous arrangements and in which ready-made components can be utilized. A power transmission arrangement for a compactor, in which a roller is installed rotatably by its ends in both end-pieces of a roller frame, in such a way that there are bearing assemblies supporting the end of the roller in both end pieces, and, in at least one end of the roller there is a ready-made hub motor, which is arranged to rotate the roller, and which hub motor includes a casing and a flange as opposing attachment ends, with bearings between them, axially securing the attachment ends, and forming a bearing assembly supporting the end of the aforesaid roller, is characterized in that the roller is supported from the end-piece with the aid of the aforesaid hub motor, in such a way that one of the attachment ends is secured to the end of the roller and the opposite attachment end is secured to the end-piece, and that in one attachment end there is an effective universal joint, which transmits moment and permits a variation in the angle between the roller and the end-piece.
In one arrangement the hub motor and universal joint are arranged in both ends of the roller. The universal joint comprises a first fork construction attached to one attachment end; a second fork construction attached to the construction opposite to the attachment end, to either the end-piece or to the end plate of the roller, at an angle of 90xc2x0 in relation to the first fork construction; and a crosspiece connecting the fork constructions, which is attached to each fork construction with the aid of two pairs of joints, which pairs of joints are essentially in the same plane. The hub motor is stiffly attached by its casing to the end plate of the roller.
A plate construction is attached to the flange, which supports two joints arranged symmetrically in relation to the axis of rotation of the roller and at a distance from each other, thus forming the first pair of joints for carrying the crosspiece, and the end-piece is supported by means of two joints forming a second pair of joints arranged symmetrically in relation to the projection of the axis of rotation of the roller, the second joints being in turn supported with the aid of the aforesaid crosspiece. The crosspiece is formed by a circular ring arranged around the hub motor, which includes the joint pins of the aforesaid pairs of joints. A roller transmission arrangement according to the invention is arranged centrally on the axis of rotation of the roller. This also protects the transmission arrangement, which is preferably assembled from standard components, inside the roller. In addition, the roller is supported in such a way that bearings that specifically support the roller are not required in the compactor, which further simplifies the construction of the compactor""s transmission arrangement. The transmission arrangement also does not limit the maximum width of the compactor.
In the following, the invention is explained in detail, with reference to the accompanying drawings, depicting one embodiment of the invention, in which